Less common IP addresses

Most of us know about the common internal IP address reservations, and typically think of the rest of the IP addresses as public, internet accessible/routable IP address. However there is a set of several IP address in the class “D” and “E” which are not commonly used. Recently someone asked a question about a particular IP address.  I recognized it as a multicast IP address.  Here’s a table of well-known multicast IP’s:  (there are others)


Table 43-1 Link Local Addresses



All systems on this subnet

All routers on this subnet

OSPF routers

OSPF designated routers

DHCP server/relay agent


And here’s a reference if you want to find out more about many-to-one networking:  http://www.cisco.com/en/US/docs/internetworking/technology/handbook/IP-Multi.html